chore(deps): update build and runtime dependencies

[TheRealAgentK]

Summary

• update Kotlin Gradle plugin from 2.3.21 to 2.4.0
• update Gson from 2.13.2 to 2.14.0
• update OkHttp from 5.3.2 to 5.4.0 (and Okio to 3.17.0 transitively)
• update the Gradle wrapper from 9.5.1 to 9.6.1
• regenerate dependency locks and SHA-256 verification metadata as one consistent graph
• update the documented Gradle requirement

This coordinated change supersedes #299, #300, #301, and #303, whose one-line Dependabot changes could not pass the repository's strict dependency locking and verification.

Deliberately excluded

#302 (androidx.core:core 1.19.0) is not included. A real build established that Core 1.19.0 requires compileSdk 37, while this project currently compiles against SDK 36. That update should be reconsidered with an explicit Android platform/AGP migration rather than folded into routine dependency maintenance.

Validation

• ./gradlew --no-daemon --write-locks --write-verification-metadata sha256 resolveAndLockAll
• ./gradlew --no-daemon --write-locks --write-verification-metadata sha256 buildEnvironment
• ./gradlew --no-daemon spotlessCheck app:lint provider:lint app:assembleDebug provider:assembleDebug provider:test
• generated release AAR has the same class list, provider.kotlin_module name, and public JVM ABI as Maven Central 6.1.0
• generated POM was inspected: Kotlin stdlib 2.4.0, Gson 2.14.0, and OkHttp 5.4.0 are the intended consumer-visible changes
• a Kotlin 2.3.21 / AGP 9.2.1 consumer project compiled successfully against the rebuilt AAR

The CI app:connectedTest job remains the final merge gate.